Sciametry
[天]日月蚀的数学理论
🗣️ 情景例句
Why?
为什么？
There was a big choice of shops in the small town.
这个小镇上有好多商店可供选择。
It was the idea of supporting a craft on a 'pad',or cushion, of low-pressure air, ringed with a curtain of higher pressure air.
用一个气垫来支撑船体，低压空或软垫，软垫周围用高压空气环绕。